CN101457399B - Erbium sodium ion double doped strontium molybdate laser crystal and preparation method thereof - Google Patents

Abstract

The invention discloses a double-doped erbium and sodium-ion calcium molybdate laser crystal and a preparation method thereof, and relates to the artificial crystal field. A flux crystal pulling method is adopted to grow a Na+/Er3+: CaMoO4 crystal with high optical quality and larger size at the growth temperature of 1200 DEG C, the crystal rotating speed of 10-30rpm and the pulling rate of 0.4-1.0mm/h. The crystal belongs to a tetragonal system, and a space group thereof is I4(1)/a. Spectral analysis proves that the crystal has a wide absorption peak and a strong emission peak, is suitable for pumping by a laser diode (LD), and can be taken as the laser crystal to produce laser output with the wavelength ranging from 550nm to 1500nm.

Description

Erbium sodium ion double doped strontium molybdate laser crystal and preparation method thereof

Technical field

The invention belongs to artificial lens and field of crystal growth in the technical field of optoelectronic functional materials, especially relate to a kind of laser crystal material as the operation material in the solid laser.

Background technology

Laser crystals is the operation material of solid statelaser, and it refers to take crystal as matrix, by discrete luminescence center absorptive pumping luminous energy and be translated into the luminescent material of Laser output.Solid laser working substance is comprised of substrate material and active ions, and its various physics and chemistry character are mainly by the substrate material decision, and its spectral response curve and fluorescence lifetime etc. are then determined by the level structure of active ions.From nineteen sixty, succeeded in developing since the synthetic ruby pulsed laser, up to now, found hundreds of laser crystalss, but because of a variety of causes, the laser crystals that can really obtain practical application only has ten to plant.

At present, most widely used laser crystals is yttrium aluminum garnet (YAG) crystal of Nd ion doped, and it has preferably various physics and chemistry performances, and is easy to grow high optical quality, large-sized gem-quality crystal.But it is narrow that it exists spectral line of absorption, is unwell to the shortcoming of carrying out pumping with LD, and the LD pumping will be the developing direction of laser pumping source from now on.

At present both at home and abroad all actively to seek various physics, chemical property and mechanical property excellent, and be easy to the high-quality laser crystal material that grows high optical quality, large size and be suitable for the LD pumping.As a kind of important laser active ion, Er ³⁺Ion has energy level to be enriched, and emission wavelength has nine transition channels from seeing near infrared, and wherein the Laser emission of 1.5 μ m and two wave bands of 3.0 μ m is corresponding respectively ⁴I _13/2→ ⁴I _15/2With ⁴I _11/2→ ⁴I _15/2Transition between the energy level.1.5 μ m laser is to eye-safe, human cell tissue is to 3.0 μ m laser strong absorption, with Er ³⁺Ion is that the laser crystals of active ions has a extensive future in fields such as communication and medical treatment.Therefore, erbium ion becomes the choosing of the hot topic of laser crystals active ions in recent years.

Summary of the invention

The object of the invention is to develop a kind of suitable use LD pumping, new laser crystals Na ⁺/ Er ³⁺: CaMoO ₄This crystal belongs to tetragonal system, has I _{4 (1)/a}The spacer structure.Er wherein ³⁺Be as the laser active ion, replace Ca ²⁺Crystallographic site, Na ⁺As the valence state counterion, replace Ca ²⁺Crystallographic site, keep the electric neutrality of structure.We have found with Na through experiment ₂MoO ₄Be fusing assistant, adopt flux pulling technique growth Na ⁺/ Er ³⁺: CaMoO ₄The comparatively ideal growth conditions of crystal, and grown high-quality, large size Na ⁺/ Er ³⁺: CaMoO ₄Crystal (seeing embodiment).

Concrete chemical equation is as follows:

0.5xNa ₂CO ₃+(1-2x)CaCO ₃+0.5xEr ₂O ₃+MoO ₃＝Na _xEr _xCa _1-2xMoO ₄

+(1-1.5x)CO ₂↑ (1)

Na ₂CO ₃+MoO ₃＝＝Na ₂MoO ₄+CO ₂↑ (2)

Raw materials usedly be:

The medicine name	Purity	Producer
			Er 2O 3	99.999％	Changchun Applied Chemistry Research Inst., Chinese Academy of Sciences
CaCO 3	99.99％	Shanghai nasal mucus connection chemical industry company limited
			Na 2CO 3	99.99％	Shanghai the May 4th chemical reagent factory
MoO 3	99.99％	Solution on Chemical Reagents in Shanghai company of Chinese Medicine group

With mol ratio CaMoO ₄: Na ₂MoO ₄Claim sample, mixing, compressing tablet, sintering, Er at=0.7: 1～1: 0.7 ₂O ₃Then press desired concn and the Na that adds ₂CO ₃Add together.In Platinum crucible, the lower pulling growth of oxygen-enriched atmosphere (air) goes out crystal, and the parameter of crystal growth is 1200 ℃ of growth temperatures, and pull rate is 0.4～1.0 millimeter/hour, and the crystal rotating speed is 10～30 rev/mins.

With the Na that grows ⁺/ Er ³⁺: CaMoO ₄Crystal has carried out the collection of diffraction data at four-circle diffractometer, structural analysis shows, it belongs to tetragonal system, and spacer is I _{4 (1)/a}, unit cell parameters is a=b=5.25 , c=11.50

, V=317

³, D _c=4.24g/cm ³, Er ³⁺Ion is as the laser active ion, its doping content between 0.5at.-10at.%, Na ⁺Ion is as the valence state counterion, and its doping content is between 0.5at.-10at.%.

With the Na that grows ⁺/ Er ³⁺: CaMoO ₄Crystal carries out the analytical test of absorption spectrum, fluorescence spectrum and fluorescence lifetime etc., and the result shows: mix 1.9at.%Er ³⁺The Na of ion ⁺/ Er ³⁺: CaMoO ₄The main absorption peak of crystal is at the 521nm place, and uptake factor is 29.18cm ^-1, absorption crosssection 1.22 * 10 ^-19Cm ²Strong fluorescence emission peak is arranged near wavelength 1550nm, and the emission transition cross section is 5.16 * 10 at the 1538nm place ^-21Cm ², fluorescence lifetime is 6.6ms, because the long crystal of fluorescence lifetime can accumulate more particle at upper energy level, has increased energy storage, is conducive to the raising of device output rating and output energy.Therefore, Na ⁺/ Er ³⁺: CaMoO ₄Crystal can obtain the Laser output of relatively high power, is a kind of high conversion efficiency, low cost, high optical quality and actual application prospect is arranged and the laser crystals of use value.

Embodiment

Embodiment: flux pulling technique grow doping concentration is 1.9at.%Er ³⁺The Na of ion ⁺/ Er ³⁺: CaMoO ₄Laser crystals.

Na in molar ratio ₂CO ₃: CaCO ₃: MoO ₃: Er ₂O ₃=1: 1: 2: 0.01 accurate load weighted Na ₂CO ₃, Er ₂O ₃, CaCO ₃, MoO ₃Mixed grinding is even, behind the compressing tablet, puts into Φ 80 * 80mm ³Corundum crucible in, in retort furnace in 500 ℃ of solid state reactions 24 hours; After the taking-up, again grind compressing tablet and be warming up to again 600 ℃ of reactions 24 hours.Synthetic above sample is put into Φ 56 * 41mm ³Platinum crucible in, pulling crystal in air atmosphere, growth temperature is 1200 ℃, the crystal rotating speed is 30 rev/mins, pulling rate is in 0.5 millimeter/hour the situation, to have grown and be of a size of Φ 20 * 32mm ³High-quality Na ⁺/ Er ³⁺: CaMoO ₄Crystal.Show Er in the crystal through the ICP test ³⁺Ion content is 1.9at.%.

Claims (2)

1. erbium sodium ion double doped strontium molybdate laser crystal, it is characterized in that: the molecular formula of this crystal is Na ⁺/ Er ³⁺: CaMoO ₄, belonging to tetragonal system, spacer is I _{4 (1)/a}, unit cell parameters:

Density D _c=4.24g/cm ³, Er ³⁺Ion is as the laser active ion, and its doping content is 1.9at.%, Na ⁺Ion is as the valence state counterion, and its doping content is between 0.5at.-10at.%.

2. the preparation method of the erbium sodium ion double doped strontium molybdate laser crystal of a claim 1 is characterized in that: this crystal by adopting flux pulling technique growth, and with Na ₂MoO ₄Be solubility promoter, mol ratio is CaMoO ₄: Na ₂MoO ₄=0.7: 1～1: 0.7; The parameter of crystal growth is: 1200 ℃ of growth temperatures, 0.4～1.0 millimeter/hour of pull rate, 10～30 rev/mins of crystal rotating speeds, air atmosphere.